Light cured materials have become regularly used in dentistry. The advantages of light curing a one-part material over a two-part system are well documented. The ability to cure on command offers the dental practioner a wide degree of control over the shape and shade of a dental restoration. This inventor has discussed various methods of delivering heated dental materials, which because of the heating effect causes these materials to take on superior handling characteristics as well as improved physical properties in the polymerized state.
In the case of dental composite fillings, all these methods relate to either heating them in syringes, in compules in which they are delivered or simply heating the material directly in an external device.
New research on dental materials has shown many benefits to heating these materials prior to polymerization. Demonstrated advantages are as follows:                1. Substantially faster monomer conversion (shorter curing time) (IADR—0819 Thermal Effects on Composite Photopolymerization Monitored by Real-time NIR By Drs. M. Trujillo and J. W. Stansbury, University of Colorado Health Sciences Center, Denver, Colo., USA).        2. Greatly reduced viscosity (IADR—Composite Film Thickness at Various Temperatures By Drs. R. G. Holmes, J. S. Blalock, and F. A. Rueggeberg, Medical College of Georgia, Augusta, Ga. USA).        3. Much greater material flow offering better adaptation to tooth surface (Dr. Broome, Associate Professor, University of Alabama School of Dentistry, Birmingham, Ala., USA) Report to AdDent Quantification of Flow Increase Resulting from Preheating Composite Compules dated Jun. 6, 2003).        
Recently, research has also shown that when a composite is preheated, we can achieve much less microleakage at the cervical margin of a dental restoration (IADR—Effect of Pre-Heating Composite on Microleakage in Class II Restorations By M. N. Aksu, A.-M. L. Neme, S. Walker, F. E. Pink, J. B. Linger, and W. C. Wagner, University of Detroit Mercy, Mich., USA). Microleakage is a major factor in causing decay under a dental restoration.
The use of heated dental restorative materials has been described in U.S. Pat. Nos. 6,236,020 and 6,616,448. A method for using heated dental materials has been described in U.S. Pat. No. 6,320,162. In both of these earlier applications, I described a method and a device for heating dental materials. In the devices used in my previous applications, a widely used compule that stores the material is heated externally. One method uses a heater placed in a block of thermally conductive material another method uses a heating element embedded in a molded plastic holder that is also part of a means for dispensing material.
Previous attempts to warm dental materials have either done so in a laboratory oven or in the container it is packaged in such as a syringe or compule. While these methods work for introducing heated composite materials into the mouth, they suffer from several drawbacks. In the case of heating a syringe, a large bulk of material is heated needlessly, and the heating time is long. In the case of heating a compule (dose package), the heating time is shortened but still significantly long. In the case of heating material expressed from a syringe onto a heated surface, the material needs to be first picked up, then introduced into the dental cavity and then repeated with each layer, also in a time consuming procedure. The invention described herein eliminates these drawbacks. In this invention, the heat is generated directly within the compule itself, and in so doing, creates a very efficient method of heat transfer from the source of heat directly into the material to be heated.
Many dentists have found it useful and convenient to dispense restorative composite, root canal filling materials; dental bleach as well as dental sealants and coatings directly from a pre dosed compule. Currently, the various compules on the market are made from polyethylene either high (HDP) or low density (LDP) as well as other commonly used plastics.